Substrate should hold enough water for your plants without becoming mud. Bark and mineral grit add air; coir and sphagnum hold moisture.
Use the Substrate Mixer to explore recipes, then adjust for your vessel size and plant list.
Define good substrate
A mix that stays springy when moist — not soup, not brick.
Materials lexicon
Coir/sphagnum for water, bark/pumice for air, charcoal for traditional freshness, litter for bioactive life.
Aftercare
Substrate compresses over months. Top up gently; do not stab roots while fluffing.
Troubleshooting
Sour smell: too wet and dense. Hydrophobic patches: mix dried hard — remoisten gradually.
